Vestibular Medical Diagnostic Testing

Question 1

Vestibular Function Testing

Answer 1

• electronystagmography (ENG)
• videonystagmography (VNG)
• rotary chair
• audiometric testing
• posturography

Question 2

ENG

Answer 2

• record eye movements by using electrodes around the eye
• uses electrical field changes to estimate the position of the eyes - indirect method
• not used very frequently anymore (small kids/babies or when ptosis is present)

Question 3

VNG

Answer 3

• Video system to observe and record video of eye mvmts
• Movements are translated into representation of yaw (no), pitch (nod) and roll (tilt)

Question 4

Components of ENG and VNG

Answer 4

• Oculomotor exam (saccades, SP, gaze holding)
• Assess spontaneous nystagmus
• Positional testing - Dix Hallpike and roll test
• Caloric testing

Question 5

Caloric Irrigation testing

Answer 5

• One peripheral organ at a time
• Only evaluates horizontal at low freq (0.004 hz)
• Stim canal with a change in temp (water or air)
• COWS - cold opposite inhibits, warm same excites
• Creates a gradient, will see less change in affected ear.

Question 6

Caloric testing results

Answer 6

• Irrigation w cool on right (inhibits) results in LB nystagmus
• Irrigation w warm on the right (excites), results in RB nystagmus

Question 7

Interpret caloric test

Answer 7

• Avg peak velocity for each of: R warm, L warm, R cool, L cool
• UL weakness results in reduced vestibular response
• Comparing R to L: >25-30% DIFFERENCE is SIGNIFICANT
• Gold standard for UL loss, only works w BL if complete loss

Question 8

Rotary Chair Testing

Answer 8

• Differentiate between compensated and uncompensated UL vestibular loss.
• Identifies BL loss (gold standard)
• Evaluates higher frequencies (.01-1hz)

Question 9

Posturography

Answer 9

Used to quantify balance
CANNOT diagnose

Question 10

Audiometric testing

Answer 10

Determines type of hearing loss

Question 11

Vestibular Suppressants

Answer 11

• Antivert/meclizine
• Recommended for acute mgmt only
• Likely to affect BPPV or VNG testing

Question 12

Anti-nausea medication

Answer 12

• Zofran/compazine (may improve early tx tolerance)
• May suggest to take before BPPV tx

Question 13

Anti-anxiety/anti-depression

Answer 13

Used as potential assistant to tx of PPPD and may help other pts that are extremely anxious or depressed about their condition

Question 14

Steroid pack

Answer 14

• Used for neuritis if caught early

Question 15

Surgical mgmt

Answer 15

• Menieres: vestibular n resection, gentamycin injection
• Acoustic neuroma/schwannoma resection